• Korean Journal of Heritage: History & Science
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• v.53 no.4
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• pp.78-99
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• 2020

The Buddha triad and 16 Arhat statues carved on the rock surface at Seongbulsa temple is the only domestic remaining example of all 16 Arhats, so its academic value is very high. However, it is severely damaged and so required a stability evaluation through study of digital documentation and precise diagnosis for the purpose of comprehensive conservation. This process established that the Buddha statues were of similar scale, while the Arhats showed a wide variety of sizes, and the two kith and kin in the volume were larger than the Arhats. It was estimated that the statues of food for Buddha are similar to the Arhat statues, and most of the statues are well-formed. The rock used to carve the Buddha statues is banded gneiss with distinct foliation, alternating between white bands of quartz and feldspar and black bands composed of biotite. The Buddha statues have been damaged by physical weathering, discoloration, and biological contamination. In damage evaluations, joint (3.6 crack index), peeling (5.2%), exfoliation (1.7%), and falling off (0.1%) were observed on the rock surface of the Buddha statues. In particular, due to severe biological weathering, stage 9 and 10 biological coverage of the rock surface accounted for 57.5% of the total area, and stages 5 to 8 also accounted for a high share at 22.3%. The discoloration factors were shown to be dark brown and white with Fe, Ca, and S, and a large amount of C detected in the blackened contaminants, and the damage weight high in all areas. Discontinuities in different directions were identified in the rock surface. Analysis of potential rock failure types indicated that there is a possibility of plane and toppling failure, but wedge failure is unlikely to occur. The mean ultrasonic velocity of the main rock surface was 2,463m/sec, the lower part of the left side with a large number of joints was relatively low, and the highly weathered (HW) type to the completely weathered (CW) type concentrated distribution, showing weak properties. For the Buddha statues, conservation treatment is required for about 14.9% of micro cracks and 58.9% of exfoliation cracks. In addition, in order to improve the conservation environment of the Buddha statues, maintenance of drainage and ground preparations for the rock surface gradient and plants are necessary, and protection facilities should be reviewed for long-term conservation and management purposes.

• Journal of the Korean Geotechnical Society
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• v.39 no.12
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• pp.47-60
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• 2023

At present, in South Korea, there is a growing concern regarding solar power facilities installed on slopes because they are prone to damage caused by natural disasters, such as heavy rainfall and typhoons. Each year, these solar power facilities experience soil erosion due to heavy rainfall and foundation damage or detachment caused by strong wind loads. Despite these challenges, the interaction between the ground and structures is not adequately considered. Current analyses primarily focus on the structural stability under external loads; the overall facility site's stability-excluding the solar structures-in relation to its surrounding slopes is neglected. Therefore, in this study, we use finite-difference method analysis to simulate the behavior of the foundation and piles to assess changes in lateral displacement and bending stress in piles, as well as the safety factor of sloped terrains, in response to various influencing factors, such as pile diameter, spacing between piles, pile-embedding depth, wind loads, and dry and wet conditions. The analysis results indicate that pile spacing and wind loads significantly influence lateral displacement and bending stress in piles, whereas pile-embedding depth strongly influences the safety factor of sloped terrains. Moreover, we found that under certain conditions, the design criteria in domestic standards may not be met.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.448-448
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• 2012

최근에 pH 감지막의 감지감도특성을 평가하기 위해 electrolyte insulator semiconductor (EIS) 구조가 유용하게 이용되고 있다. EIS는 간단한 구조와 pH 용액에 빠른 응답속도, 낮은 단가 및 집적이 용이하다는 장점이 있다. EIS 구조에서 화학적 용액에 대한 감지감도 평가 중 가장 중요하게 작용하는 부분이 감지막이다. 이 감지막은 감지 대상 물질과 물리적으로 직접 접촉되는 부분으로서 일반적으로 기계적/화학적 강도가 우수한 실리콘 산화막($SiO_2$)이 많이 사용되어져 왔다. 최근에는 기존의 $SiO_2$ 보다 성능이 향상된 감지막을 개발하기 위하여 $Al_2O_3$, $HfO_2$, $ZrO_2$, 그리고 $Ta_2O_5$와 같은 고유전 상수(high-k)를 가지는 물질들을 EIS 센서의 감지막으로 이용하는 연구가 활발하게 진행되고 있다. High-k 물질 중 $Al_2O_3$는 산성에서 알칼리성 영역까지의 넓은 화학안정성을 가지며 화학용액에 대해 내구성이 우수한 특성을 가진다. $HfO_2$은 내식성이 뛰어나며 출력특성이 높은 장점을 가진 물질이다. 본 실험에서는 특성이 다른 두 물질을 EIS의 감지막으로 각각 사용하여 두께에 따른 의존성을 평가하였다. 제작한 EIS 구조의 pH 센서를 바이오 센서에 적용하였을 때 신호대 잡음비(SNR: signal to noise)가 여전히 취약하다는 문제점이 있었다. 이런 문제점을 보완하기 위하여 감지막의 물리적 두께는 점점 얇아지게 되었고 그 결과 높은 출력 특성을 얻게 되었지만, 감지막이 얇아짐에 따라서 화학 용액 중의 이온 침투로 인한 감지막 자체의 손상 또한 심각한 문제로 대두되었다. 이로 인해 최적화 된 감지막의 두께를 얻을 필요가 있다. 결론적으로 $Al_2O_3$, $HfO_2$ 두 감지막 모두 두께가 23 nm일 때 가장 우수한 특성을 보였으며, $Al_2O_3$를 감지막으로 사용하였을 경우 화학적 용액에 대해 내구성이 뛰어났고, $HfO_2$을 사용하였을 때에는 화학적 용액에 대한 안정성 보다는 pH 용액변화에 따른 향상된 감지감도특성을 보였다.

• Journal of Korean Neurosurgical Society
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• v.30 no.10
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• pp.1210-1219
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• 2001

Introduction : The purpose of this study was to analyze the safety, pullout strength and radiographic characteristics of unicortical and bicortical screws of cervical facet within cadaveric specimens and evaluate the influence of level of training on the positioning of these screws. Methods : Twenty-one cadavers, mean 78.9 years of age, underwent bilateral placement of 3.5mm AO lateral mass screw from C3-C6(n=168) using a slight variation of the Magerl technique. Intraoperative imaging was not used. The right side(unicortical) utilized only 14mm screws(effective length of 11mm) while on the left side to determine the length of the screw after the ventral cortex had been drilled. Three spine surgeons(attending, fellow, chief resident) with varying levels of spine training performed the procedure on seven cadavers each. All spines were harvested and lateral radiographs were taken. Individual cervical vertebrae were carefully dissected and then axial radiographs were taken. The screws were evaluated clinically and radiographically for their safety. Screws were graded clinically for their safety with respect to the spinal cord, facet joint, nerve root and vertebral artery. The grades consisted of the following categories : "satisfactory", "at risk" and "direct injury". Each screw was also graded according to its zone placement. Screw position was quantified by measuring a sagittal angle from the lateral radiograph and an axial angle from the axial radiograph. Pull-out force was determined for all screws using a material testing machine. Results : Dissection revealed that fifteen screws on the left side actually had only unicortical and not bicortical purchase as intended. The majority of screws(92.8%) were satisfactory in terms of safety. There were no injuries to the spinal cord. On the right side(unicortical), 98.9% of the screws were "satisfactory" and on the left side(bicortical) 68.1% were "satisfactory". There was a 5.8% incidence of direct arterial injury and a 17.4% incidence of direct nerve root injury with the bicortical screws. There were no "direct injuries" with the unicortical screws for the nerve root or vertebral artery. The unicortical screws had a 21.4% incidence of direct injury of the facet joint, while the bicortical screws had a 21.7% incidence. The majority of "direct injury" of bicortical screws were placed by the surgeon with the least experience. The performance of the resident surgeon was significantly different from the attending or fellow(p<0.05) in terms of safety of the nerve root and vertebral artery. The attending's performance was significantly better than the resident or fellow(p<0.05) in terms of safety of the facet joint. There was no relationship between the safety of a screw and its zone placement. The axial deviation angle measured $23.5{\pm}6.6$ degrees and $19.8{\pm}7.9$ degrees for the unicortical and bicortical screws, respectively. The resident surgeon had a significantly lower angle than the attending or fellow(p<0.05). The sagittal angle measured $66.3{\pm}7.0$ degrees and $62.3{\pm}7.9$ degrees for the unicortical and bicortical screws, respectively. The attending had a significantly lower sagittal angle than the fellow or resident(p<0.05). Thirty-three screws that entered the facet joint were tested for pull-out strength but excluded from the data because they were not lateral mass screws per-se and had deviated substantially from the intended final trajectory. The mean pull-out force for all screws was $542.9{\pm}296.6N$. There was no statistically significant difference between the pull-out force for unicortical($519.9{\pm}286.9N$) and bicortical($565.2{\pm}306N$) screws. There was no significant difference in pull-out strengths with respect to zone placement. Conclusion : It is our belief that the risk associated with bicortical purchase mandates formal spine training if it is to be done safely and accurately. Unicortical screws are safer regardless of level of training. It is apparent that 14mm lateral mass screws placed in a supero-lateral trajectory in the adult cervical spine provide an equivalent strength with a much lower risk of injury than the longer bicortical screws placed in a similar orientation.

• Tuberculosis and Respiratory Diseases
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• v.63 no.5
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• pp.423-429
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• 2007

Background: Alveolar recruitment (RM) is one of the primary goals of respiratory care for an acute lung injury (ALI) and acute respiratory distress syndrome (ARDS). The purposes of alveolar recruitment are an improvement in pulmonary gas exchange and the protection of atelectrauma. This study examined the effect and safety of the alveolar RM using pressure control ventilation (PCV) in early ALI and ARDS patients. Methods: Sixteen patients with early ALI and ARDS who underwent alveolar RM using PCV were enrolled in this study. The patients data were recorded at the baseline, and 20 minutes, and 60 minutes after alveolar RM, and on the next day after the maneuver. Alveolar RM was performed with an inspiratory pressure of $30cmH_2O$ and a PEEP of $20cmH_2O$ in a 2-minute PCV mode. The venous $O_2$ saturation, central venous pressure, blood pressure, pulse rate, $PaO_2/FiO_2$ ratio, PEEP, and chest X-ray findings were obtained before and after alveolar RM. Results: Of the 16 patients, 3 had extra-pulmonary ALI/ARDS and the remaining 13 had pulmonary ALI/ARDS. The mean PEEP was 11.3 mmHg, and the mean $PaO_2/FiO_2$ ratio was 130.3 before RM. The $PaO_2/FiO_2$ ratio increased by 45% after alveolar RM. The $PaO_2/FiO_2$ ratio reached a peak 60 minutes after alveolar RM. The Pa$CO_2$ increased by 51.9 mmHg after alveolar RM. The mean blood pressure was not affected by alveolar RM. There were no complications due to pressure injuries such as a pneumothorax, pneumomediastinum, and subcutaneous emphysema. Conclusion: In this study, alveolar RM using PCV improved the level of oxygenation in patients with an acute lung injury and acute respiratory distress syndrome. Moreover, there were no significant complications due to hemodynamic changes and pressure injuries. Therefore, alveolar RM using PCV can be applied easily and safely in clinical practice with lung protective strategy in early ALI and ARDS patients.

• Tuberculosis and Respiratory Diseases
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• v.42 no.4
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• pp.522-534
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• 1995

Background: In the pathogenesis of acute lung injury induced by lipopolysaccharide(LPS), oxygen radiclls are known to be involved in one part. Superoxide dismutase(SOD) protects oxygen radical-induced tissue damage by dismutating superoxide to hydrogen peroxide. In eukaryotic cells, two forms of SOD exist intracellularly as a cytosolic, dimeric copper/zinc-containing SOD(CuZnSOD) and a mitochondrial, tetrameric manganese-containing SOD(MnSOD). But there has been little information about SOD gene expression and its regulation in pulmonary alveolar macrophages(PAMs). The objective of this study is to evaluate the SOD gene expression induced by LPS and its regulation in PAMs of rat. Method: In Sprague-Dawley rats, PAMs obtained by broncholaveolar lavage were purified by adherence to plastic plate. To study the effect of LPS on the SOD gene expression of PAMs, they were stimulated with different doses of LPS($0.01{\mu}g/ml{\sim}10{\mu}g/ml$) and for different intervals(0, 2, 4, 8, 24hrs). Also for evaluating the level of SOD gene regulation actinomycin D(AD) or cycloheximide(CHX) were added respectively. To assess whether LPS altered SOD mRNA stability, the rate of mRNA decay was determined in control group and LPS-treated group. Total cellular RNA extraction by guanidinium thiocyanate/phenolfchlorofonn method and Northern blot analysis by using a $^{32}P$-labelled rat MnSOD and CuZnSOD cDNAs were performed. Results: The expression of mRNA in MnSOD increased dose-dependently, but not in CuZnSOD. MnSOD mRNA expression peaked at 8 hours after LPS treatment. Upregulation of MnSOD mRNA expression induced by LPS was suppressed by adding AD or CHX respectively. MnSOD mRNA stability was not altered by LPS. Conclusion: These findings show that PAMs of rat could be an important source of SOD in response to LPS, and suggest that their MnSOD mRNA expression may be regulated transcriptionally and require de novo protein synthesis without affecting mRNA stability.

• Explosives and Blasting
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• v.14 no.2
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• pp.71-80
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• 1996

A series of nurmerical analysse for the earhtquake of Iran railway tunnles under construction by NATM(New Astrian Tunnelling Method) were careid out throuth a pseudo-dynamic analyses techique used in a FFM computer program, DWTAP(Daewoo Tunnel Analysis Program), and the results are described in the paper. The analyses were performErl for two case;one is for the primary supports and the other is for the rompletEd permanent roncrete lining. The horizontal and verical groW1d accelerations for the design were estimatEd as 0.34 g and 0.23 g, respectively based on the historical reismic rerords in the proj3et area and the empirical equations. The results show that the turmel would be safe W1der the anticipitOO earthquake motion with the permanent roncrete lining, but some minor cracks rnigt be developErl in the primary shotcrete lining without any significant structural damages.

• The Journal of Korean Physical Therapy
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• v.11 no.3
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• pp.71-79
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• 1999

본 연구의 목적은 균형 훈련이 중추신경계 손상자들의 자세 조절 및 중추감각신경전도로에 미치는 영향을 규명하는데 있다. 연구대상자는 중추신경계 손상자로써 실험군 10명, 통제군 10명 등 총 20명을 선정하였으며, 실험군은 본 연구의 훈련 프로그램에 따라 12주간 force platform을 이용하여 균형훈련을 실시토록하였다. 자세조절 변인의 측정은 운동처치 전, 처치 후 8주 및 12주 후에 대상자들의 동적 및 정적 자세에서의 흔들림을 Dynamic Balance System을 이용하여 측정하였고, 체성감각 유발전위의 말초신경 근위부 유발전위$(N_9)$ 잠복기, 척수 유발전위$(N_{13})$ 잠복기, 뇌 유발전위 $(N_{20})$ 잠복기는 Neurotec을 이용하여 측정 분석한 결과 다음과 같은 결론을 얻었다. 1. 정적 자세 조절 요인의 경우, 좌우 흔들림과 전후 흔들림은 실험군에서 8주 후부터 유의하게 (p<.05) 감소하였고, 실험군이 통제군에 비해 운동처치 8주 및 12주 후에 각각 유의하게(P<.05, P<.01) 흔들림이 감소하였다. 2. 전후 이동면과 전후 기울기면에서 동적 자세 조절의 변화는 전후 이동면에서 좌우 흔들림과 전후 흔들림은 실험군에서 8주 후부터 유의하게 (P<.05) 감소하였으며, 실험군이 통제군에 비해 운동처치 8주 및 12주 후에 각각 유의하게 (P<.05, p<.01) 흔들림이 감소하였다. 3. 체성감각 유발전위의 잠복기 변화는 실험군과 통제군에 있어서 말초신경 근위부 유발전위$(N_9)$ 잠복기와 척수 유발전위$(N_{13})$ 잠복기가 다소 증가하였으나 유의한 차이는 나타나지 않았으며, 실험군에 있어서 뇌 유발전위 $(N_{20})$ 잠복기는 8주 후부터 유의하게 (P<.05) 증가하였다. 이상의 결과를 종합해 볼 때, 12주의 균형 훈련은 자세 조절에 있어서 전후와 좌우의 흔들림을 감소시킴으로써 정적인 상태나 동적인 상태에서의 자세 안정성을 증가시킬 수 있음을 시사하고 있다. 이는 자세 조절에 필요한 항중력근의 긴장성 수축을 유발시킬 뿐만 아니라 근육 긴장분포를 조절할 수 있다는 것으로 신경근 조절 기능의 향상을 의미하는 것으로 사료된다. 또한 뇌 유발전위 $(N_{20})$ 잠복기의 증가는 중추신경계의 감각기능의 신경학적 회복을 의미하는 것으로 중추신경계의 감각 운동통합에도 영향을 미쳐 운동기능의 향상을 기대할 수 이을 것으로 사료된다.

• Journal of the Korean Arthroscopy Society
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• v.4 no.2
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• pp.117-122
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• 2000

Purpose : To compare the mid term with long term follow up results of the anterior cruciate ligament(ACL)> reconstruction using patellar tendon. Materials and Methods : Seventy-six cases, which could be followed up more than 2 years were included in this study. They were classified into two groups, mid-term group(41 cases) with mean follow-up periods of 2 years and 10 months and long-term group(35 cases) off years and 6 months. Clinical and radiological results and peripatellar complications were evaluated & compared. Results . There was no statistically significant difference in radiological finding and anterior instability between two groups. However, the incidence of anterior knee pain, paresthesia at incision site, kneeling pain, crepitus and quadriceps weakness was lower in long-term group than in mid-term group. Conclusion : ACL reconstruction using patellar tendon graft could successfully restone the stability of knee joint, but there are some complications in donor site and patellofemoral joint. However this complications were gradually decreased with long term follow-up.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.2
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• pp.235-239
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• 2019

High-grade liver injury is associated with high morbidity and mortality rates. We report successful emergency angioembolization and early interventional radiology support to manage a high-grade liver injury in a 29-year-old man who presented following a fall during parachute training. Upon arrival, his blood pressure was 80/40 mmHg, and emergency ultrasonography showed a liver injury with perihepatic fluid collection. The patient's blood pressure reduced to 60/40 mmHg, and emergency angiography was performed without computed tomography (CT) (door to puncture time 36 min). After angioembolization, his blood pressure returned to 120/77 mmHg. Subsequent CT revealed no additional bleeding or hollow viscus injury. He was admitted to the Intensive Care Unit and discharged without complications 30 days after admission. In this case, emergency angioembolization (without performing CT) could successfully and safely treat a hemodynamically unstable patient with a high-grade liver injury.